Date: Fri, 16 Dec 2005 15:37:15 +0100 (CET) From: "Lars Kristiansen" <lars+lister.freebsd@adventuras.no> To: freebsd-questions@freebsd.org Subject: Re: swap - 2 HDs Message-ID: <63972.213.236.228.129.1134743835.squirrel@mail.adventuras.no> In-Reply-To: <43A2C35E.9060206@dial.pipex.com> References: <20051216123357.4932.qmail@web31611.mail.mud.yahoo.com> <20051216131451.GV2413@merkur.atekomi.net> <43A2C35E.9060206@dial.pipex.com>
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> Will Maier wrote: > >>On Fri, Dec 16, 2005 at 09:33:57AM -0300, Aguiar Magalhaes wrote: >> >> >>>Is It recommended to configure swap area in both HDs ?? >>> >>> >> >>I don't see the point -- swap is where pages that don't fit in your >>real memory go. It's less optimal than real memory in terms of >>latency, but I don't see how two disks would make swap performance >>much better. >> >> > This is contrary to the "usual" advice which is to split swap across > disks AFAIK. I've never done any benchmarks, but my gut feeling would > be that if the disks were on separate controllers, and if the machine > did swap regularly then two swap partitions would be beneficial. Even > on the same controller it could easily make a difference since > individual IDE/SATA disks can't actually reach the performance of the > channel as a whole. >From observation one can see that freebsd use the swap-partitions equally. You probarly do want to make swap-partitions on all disks, but you may later want to swapoff what is on the most busy disk if the disks are unequally busy. -- Lars > > Given that these are large hard disks, what's 2 or 4Gb in the grand > scheme? A drop in the ocean, so I would (and do) put swap on both. > > Of course, if the machine actually swaps regularly then investing in > more RAM would give the best performance! > > --Alex > > PS If the two disks are larger than your actual needs, then you might > want to consider emergency scenarios like one of your disks dieing. If, > for example, you put a spare, bootable version of FreeBSD on the 2nd > disk to aid recovery then that OS will need a swap partition anyway and > you might as well use it regularly. $0.02 > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" >
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